PR #155 review round 2.
Finding 1 (must fix): Q#BP7 item 1 — "growth reaching the live tail
re-arms follow (top -> None), only when no selection is active" — was
never implemented. `at_bottom` is the instantaneous geometric readout
`scroll_offset == 0`, which a still-anchored view satisfies whenever it
happens to be tall enough to reach the tail, so the round-1 assertion
could not see the gap: the next rows the child printed pushed the
anchored view back into history.
`rearm_follow_on_growth` now clears `top` when a viewport-size
declaration makes the view cover the tail and no selection is frozen,
and every size-declaring path (`snapshot_for_view`, `record_view_size`,
`view_status_for_size`) routes through one `declare_view_size` helper so
grid and semantic declarations cannot disagree. `scroll_view` and
`begin_selection` deliberately stay out: they write `top` themselves,
and `scroll_view` already owns the scroll-driven arm.
New acc32b is the pin the review asked for: scroll into history, grow
past the tail, then release a SECOND burst of child output through a
filesystem gate and assert the view moved with it.
Finding 2: the PTY fixtures emitted LF-only output, which staircases
rightward until every row clips to blanks past the viewport width — so
the round-1 anchor assertions compared "" with "" and could not fail.
Both fixtures now emit CRLF, and each anchor comparison is guarded by
`assert!(!top_before.is_empty())`.
Finding 3: acc33's contrast case asserted nothing, and the behavior it
claimed was false as coded. With the re-arm in place it is true and now
asserted: clearing the selection at the same geometry re-arms follow and
leaves the frozen anchor.
Finding 4: `start_run` gated the panel branch on `display == "panel" or
already_in_panel(..)`, so an explicit `display = "current"` lost to the
inference — and that value is the documented user-facing opt-out from
the Stage 3 default flip. Now gated on OMISSION. acc19b gains the
explicit-"current" case.
Finding 5: `window_drag` is a `HashMap<FrontendId, WindowDragState>`, so
a peer's mode-line press can no longer steal or clear another
frontend's in-flight gesture, and concurrent drags are legal. Cleared on
detach. acc30c gains the mode-line-press case.
Minor: `pmacs.window.buffer()` resolves both arms through the acting
frontend using the shared `lookup_window` / `selected_window` validators
rather than re-implementing them beside an ambient `active_buffer_id()`.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Levi Neuwirth
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